Manufactured electronic products may have limits on the amount of electromagnetic radiation that they are allowed to emit. For example, governmental regulations define maximal electromagnetic radiation emission limitations. Part of these limitations are focused on the radio frequency and microwave (hereinafter RF) portion of the electromagnetic spectrum. Therefore, one part of product design includes ensuring that the electronic circuitry has minimal RF emission and that the emissions are confined inside of an enclosure. Ensuring that emissions are confined inside of an enclosure involves detecting possible leakages, or gaps, in the enclosure from which RF radiation can escape.
Current techniques for detecting such gaps include using a “sniffer” to detect leakages. A sniffer is a single antenna that can receive RF radiation. If the sniffer detects RF radiation, the antenna outputs a signal to a spectral analyzer or an oscilloscope. As the sniffer moves over the surface of the enclosure, the strength of the signal varies, allowing the operator to determine the precise location of the leakage. Scanning an entire electrical device with a sniffer can be time consuming and expensive. The sniffer also cannot take an instantaneous image of the RF emissions from the device.
Another current technique for detecting RF leakage includes a “scanner.” In a scanner setup, an antenna sensitive to RF frequencies remains stationary and the device under test (DUT) rests on a moveable table. The table moves beneath the antenna. This method can be used to generate an image of the RF emission profile of the DUT, but it is time consuming as the operator must wait for the table to move so that each point of interest on the DUT passes beneath the antenna. A scanner is unable to produce an instantaneous image of the RF emission profile of the DUT.